The Plague Dogs is not your kids film, as a matter of fact, I couldn't see a kid wanting to see this at all. But this isn't a bad thing, this movie isn't even trying to be a kids film to start with, the film holds you and does not let go. This tale of two dogs's adventues to try and stay alive and stay out of the testing center they were in at the beginning and while many wouldn't agree with me, this film ends the only way it could (though you have to read the book to understand it).
Much like Watership Down, the things they had to cut out are minor, but there are times you'll scratch your head wondering why they said that, but I can tell you, if you want to know, READ THE BOOK!!!
This is one of the finest flicks ever made, simple as that
P.S. one of the soldiers is voiced by Patrick Stewart, not brought up on the earlier screens